Wood-cleated boxes have long been used to package heavy equipment such as lawn and garden tractors, lawn mowers, snowmobiles, engines, air conditioners, and the like. The conventional wood-cleated box consists of a wood reinforced corrugated paperboard body, a wooden top frame and a wooden base. Typically, the corrugated paperboard body is rectangular with opposing end walls and opposing side walls. At least one interior surface of a wall of the currugated body is provided with a reinforcement cleat vertically aligned and attached thereto to provide stacking strength for the container. The reinforcement is typically made of a hard wood or wood-like material. The corrugated paperboard body gives the container definition and maintains the position of the vertical wood reinforcement cleats. The base member, often referred to as a skid or pallet, supports the container and the product packed therein. The top frame can be considered to be a base for closing off the container, and the top frame further provides a constant surface upon which another container may be stacked. The top frame aids in distributing a top load imposed on the container; for example, a top load is imposed by a smaller package placed on top of the container in a less-than-load shipment. The arrangement of the wood-cleated box seeks to prevent collapse of the corrugated body when handled or shipped, even in multi-unit stacks, typically having between two and six units. Such wood-cleated boxes with mating bases and top frames provide stacking strength for packing, storing, and shipping heavy articles.
The end walls of the corrugated body typically are each provided with a pair of the vertical reinforcement cleats. The cleats attach to the wall near the corners defined by the end wall and a side wall of the corrugated body. The bottom end of the vertical reinforcement cleats are finished with a notch or bevel which matingly engages a notch or bevel on the base to interlock the container and the base. Similarly, the upper end of the vertical reinforcement cleats also defines a notch or bevel for engaging a mating notch or bevel in the top frame. The top frame, the vertical cleats, and the base are thereby interlocked together. Loads on the container are transmitted by the vertical cleats to the top frame and the base.
Each of the side walls of the corrugated body can also be provided with a vertical reinforcement cleat that attach in the center between the end walls. Such center cleats provide further support for the top frame and a top load imposed by other containers stacked thereon. The vertical reinforcement cleats for the side walls are typically made of a hard, dense wood or similar material. Often the lower and the upper ends of the center cleats are finished for engaging the cleat with the base and the top frame, respectively. For instance, the lower end of the cleat is cut to define a tenon which is received in a mortise on the base. The upper end of the cleat can be notched or beveled to matingly engage a notch or bevel on the top frame.
The wood-cleated boxes discussed above are particularly suited for handling by clamp truck, because the notches, the bevels, and the mortise/tenon connections generally restrain the vertical reinforcement cleats from moving laterally out of connection with the base or top frame during handling. The clamp truck (sometimes called a squeeze truck) uses hydraulically operated platens which exert pressure of sufficient force on the sides of the container to allow the container to be lifted by the truck for moving and stacking in a warehouse for storage or in a trailer for shipment. Clamp handling equipment is often preferred over forklift trucks as the box then does not require external skid boards such as are used with a box adapted for fork-lift handling.
The pressure of the horizontal force applied by the platens to the wood-cleated box, however, may break or otherwise separate the vertical cleat from the base or the top frame. For instance, the notches and bevels are typically cut to a depth between about one-third and one-half or more of the thickness of the wood member of the base or the top frame. Such cuts lead to structural weakening of the member. Excessive horizontal force on the cleat may break the notch at the narrow portion or move the cleat inwardly from the side of the container and out of engagement with the base or the top frame. Such a damaged support cleat may cause the container to collapse, particularly if other containers are stacked thereon. Collapse or damage to the container may lead to damage to the article packaged therein. Also, the manufacture of the members of the base (and top frame) with the notches and bevels is time consuming and labor intensive. Special machinery may be required to cut the features in the members. Assembly of the base and the top frame is labor intensive to align and attach the members together. Should the wood pieces be mis-cut or mis-assembled, the base and top frame would be improperly formed for receiving the end of the vertical cleat attached to the corrugated body. Also, the members of the base or top frame may not be properly assembled or mis-aligned, so that the notch or bevel in the member is incapable of receiving and holding the vertical cleat.
Thus, there is a need in the art for a socket that readily and easily attaches to a base or top frame for receiving an end of a vertical reinforcement cleat attached to a wall of a corrugated paperboard body.